1. Field of the Invention
The present invention relates to a planar dual polarization antenna, and more particularly, to a wide-band planar dual polarization antenna capable of effectively reducing antenna dimensions, meeting 45-degree slant polarization requirements, generating linearly polarized electromagnetic waves, and providing two symmetric feed-in points to generate an orthogonal dual-polarized antenna field pattern.
2. Description of the Prior Art
Electronic products with wireless communication functionalities, e.g. notebook computers, personal digital assistants, etc., utilize antennas to emit and receive radio waves, to transmit or exchange radio signals, so as to access a wireless communication network. Therefore, to facilitate a user's access to the wireless communication network, an ideal antenna should maximize its bandwidth within a permitted range, while minimizing physical dimensions to accommodate the trend for smaller-sized electronic products. Additionally, with the advance of wireless communication technology, electronic products may be configured with an increasing number of antennas. For example, a long term evolution (LTE) wireless communication system and a wireless local area network standard IEEE 802.11n both support multi-input multi-output (MIMO) technology, i.e. an electronic product is capable of concurrently receiving and transmitting wireless signals via multiple (or multiple sets of) antennas, to vastly increase system throughput and transmission distance without increasing system bandwidth or total transmission power expenditure, thereby effectively enhancing spectral efficiency and transmission rate for the wireless communication system, as well as improving communication quality. Moreover, MIMO communication systems can employ techniques such as spatial multiplexing, beam forming, spatial diversity, pre-coding, etc. to further reduce signal interference and increase channel capacity.
As can be seen from the above, a prerequisite for implementing spatial multiplexing and spatial diversity in MIMO is to employ multiple sets of antenna to divide a space into many channels, in order to provide multiple antenna field patterns. Therefore, it is a common goal in the industry to design antennas that suit both transmission demands, as well as dimension and functionality requirements.